December 2011
2 posts
http://blog.corensic.com/2011/11/28/virtual-machine... →
Great article describing how virtual->physical address translation works in x86.
Summary
Each process gets its own private page table. The pointer to this page table will be stored in a special CR3 register upon a context-switch.
Walking the private page tables is expensive. So the entries are cached in a TLB. But that means during a context-switch, you’d to flush the entire TLB...
http://www.cloudera.com/resource/hadoop-world-2011-... →
Video of @tlipcon’s talk on Hadoop Performance from Hadoop World 2011 is now available on the Cloudera website. Todd walks through a bunch of performance fixes he did to Hadoop recently, and it’s an interesting list of common perf optimization tricks:
keeping TCP conns alive in HDFS rather than establishing new ones each time
making Hadoop behave better with the Linux pagecache...